As is generally known, plastic containers can be already be labeled in the course of the production process through so-called in-mold labeling by introducing the labels in the blow mold before blow molding of the containers is executed.
In rotary blow molders the labels are, as described e.g. in U.S. Pat. No. 6,649,119 B2 removed from stationary magazines by rotating transfer pallets, transferred to a transfer wheel provided with radially displaceable and rotatable transfer arms and arranged between the feeder star wheel and the discharge star wheel, and introduced by these transfer arms into the open blow mold. The above arrangement is, however, disadvantageous not only insofar as the separate transfer pallets used for removing the labels entail costs but also insofar as, on the one hand, only a small angular range of the machine can be utilized for inserting the labels into the blow molds and, on the other hand, the angular range of the machine that is available for blowing molding is reduced to an undesirable extent. It follows that the manufacturing efficiency of the machine is not satisfactory.
U.S. Pat. No. 5,266,149 A describes a labeling system for a rotary blow molder in the case of which a label magazine and a transfer arm are arranged directly on the blow wheel for each mold half. This system is, however, disadvantageous insofar as a large number of magazines and transfer systems is required and insofar as the magazines on the blow wheel are difficult to access during the production process.
WO 00 785 26 A1 describes a stationary labeling system in which two grippers, which are directed away from one another, carry out an oscillatory up and down movement between two stationary label magazines and two blow mold halves of a blow wheel, the grippers being first moved horizontally away from each other at the reversal points so as to pick up the labels from the magazines and introduce them into the blow mold halves and being then moved towards each other so as to change between the reversal points. Such a cycle-type machine is, however, disadvantageous insofar as a sufficiently high manufacturing efficiency cannot be achieved.